Having saline injected into the breasts in order to temporarily enlarge them.
Girl #1: My tits feel weird.
Girl #2: What do you mean?
Girl #1: I did Party Tits at the share this weekend.
Girl #2: What??
Girl #1: Party Tits. You get saline injected into them, and they get really big. It wears off in a few days. The guys love it.